Improvement in processes of printing on and decorating metal surfaces



"LETNI ED ST TES PATENT Grrror.

LEGRAND B. SMITH, OF NEW YORK, N. Y.

IMPROVEMENT IN PROCESSES 0F PRINTING ON AND DECORATING METAL SURFACES.

Specification forming part of Letters Patent No. 183,336.,

April 29, 1876.

To all whom it may concern Be it known that I, LEGRAND B. SMITH, of NewYork, in the county of New York and State. of New York, have inventedcertain new and useful Improvements in Printing and Decorating Metal;and I do hereby declare that the following is a full, clear, and exactdescription thereof, which will enable others skilled in the art towhich it appertains to make and use the same, reference being bad to theaccompanying drawings, and to the letters of reference marked thereon,which form a part of this specification. Y

My invention relates to decorating and printing on tinned iron orsimilar combination metal, having as its object an indelible design andan imprint, which cannot be disturbed or defaced by a reagent, but, onceset, will retain its color and conformation, though subjected to violentalterative action.

It is well known in the art that tin or other smooth, bright-surfacedmetal will not hold an imprinted color when treated with alcohol orother test reagent, or long subjection to heat.

My invention consists, broadly, in heatinga printed roughened metallicpl-atemore in detail appearing from the following description, in which,as auxiliary to my main idea, my invention further consists in'a thingummy coat applied to the print prior to the heat application, as afirst subsidiary step, while as a second there maybe used in place ofthe common printers ink a compound liquid in which acid and somecorresponding reacting metal enter as elements.

The plate is preferably tinned iron, of which different grades exist;for instance, pure tin is used to coat the iron forming vegetableeans,while for some other purposes sheet-iron is coated with an admixture oflead and tin. To both of these my process equally applies, andI roughenthe plate by any appropriate means, such as rollers, the well-knownsandblast, or otherwise. The plate is then passed through a printing ordecorating process, consisting in stamping a type imprint directly uponthe face of the roughened plate, the same in principle and efl'ect asprinting on paper, all ofwhich foregoing is, however, fully and at largeset forth IHfUIlIIIBd. States Let-.

dated October 17, 1876; application filed ters Patent No. 172,894.,granted me' the 1st of February, A. D. 1876.

I have thus far described matter which is covered by said LettersPatent; but the subject-matter now in hand is to cause such a printedsheet to retain its received color or printed impress. To such an end myinvention herein consists simply inthe application of heat sufficient toeffect a mechanical union or amalgamation of the print and the metalcorrugations.

I do not restrict myself to a certain or specified degree oftemperature, nor to the mode of application of same, since it is evidentthat the height of the temperature requisite to cause the angularparticles of metal to unite with the inks and insure an effectualcohesion of the two must vary, as does the density and melting point ofthe particular substance which constitutes the coating of the main orbase plate, and on which coating substance the roughened corrugationsare formed. Also, it is apparent that the means and methods of heatingthe plate may be of any agreeable nature, and the special or detaileddescription of same is unnecessary, any one skilled in the art beingcapable of readily applying the principle of my invention and employingappropriate apparatus.

In the working of this process, if a thin coating of gum, or some suchsubstance as will cover all the metallic face surface, is put on beforeapplication of heat, it will prevent oxidation of the metal, and soproduce a brighter and more finished surface. I have tried an ink'inwhich acid (nitric) was a part element. This acid was also used incombination with copper. Its action on tin helped the effect. Otheracids in combination with other metals can be used; but for practicaluses the ordinary black printing-ink will stand the test.

The above processes applied to bright metal do not produce the samertsults, and the secret lies in the fact that the roughened surface soassists the amalgamation, by allowing the foreign substances used inproducing the designs to sink, in part, below the plane of the surfaceof the metal, as to make it of practical value when finished, in that itcan be used for various commercial purposes, among )thers inthemanufacture of cans in which oeef and like substances are packed, whichare subjected to a long boiling in water. However, I do not limit myselfto the actual use of these last two mentioned measures-to wit, thegummed. surface and peculiar liquid applied; but I may omit either oneor both entire from my process of obtaining an indelible type imprint onmetal; and I desire to be understood as unqualifiedly claiming theapplication of heat to a roughened metallic surface directly upon aroughened metallic surface, and subtallic sheet, consisting'in printingjecting same to a heated temperature, substantially as and for thepurpose described.

2. In the process of indelibly printing a metal surface, prepared asabove described,

coating same with a gummy substance, whereby its oxidation uponsubjection to heat is prevented, substantially asand for the purposedescribed.

'A process of indelibly printing on metal, the same consisting inprinting 'a roughened surface with ink compounded of acid and metal,then coating with gum, and finally treating same tially as and for thepurpose described.-

In testimony that I claim the foregoing as my own I aflix my signaturein presence of two witnesses.

LEGBAND B. SMITH.

Witnesses:

SAMUEL G. BARNARD, HARRY SMITH.

to a moderate heat, substan-

